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<title>Composing Concepts</title>
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<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="boost_typeerasure.composing_concepts"></a><a class="link" href="composing_concepts.html" title="Composing Concepts">Composing Concepts</a>
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<p>
      (For the source of the examples in this section see <a href="../../../libs/type_erasure/example/compose.cpp" target="_top">compose.cpp</a>)
    </p>
<p>
      Multiple concepts can be composed using an MPL sequence.
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<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span> <span class="special">=</span> <span class="identifier">_self</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">arithmetic</span> <span class="special">:</span>
    <span class="identifier">mpl</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span>
        <span class="identifier">copy_constructible</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;,</span>
        <span class="identifier">addable</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;,</span>
        <span class="identifier">subtractable</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;,</span>
        <span class="identifier">multipliable</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;,</span>
        <span class="identifier">dividable</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;,</span>
        <span class="identifier">equality_comparable</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;,</span>
        <span class="identifier">less_than_comparable</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span>
    <span class="special">&gt;</span>
<span class="special">{};</span>
</pre>
<p>
    </p>
<p>
      Now, <code class="computeroutput"><span class="identifier">arithmetic</span></code> is a concept
      that can be used just like any of the base concepts.
    </p>
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<td align="right"><div class="copyright-footer">Copyright © 2011-2013 Steven Watanabe<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
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